In modern consumer electronics, audio capability is playing an increasingly larger role as improvements in digital audio signal processing and audio content delivery continue to happen. In this aspect, there is a wide range of consumer electronics devices that can benefit from improved audio performance. For instance, smart phones include, for example, electro-acoustic transducers such as speakerphone loudspeakers and earpiece receivers that can benefit from improved audio performance. Smart phones, however, do not have sufficient space to house much larger high fidelity sound output devices. This is also true for some portable personal computers such as laptop, notebook, and tablet computers, and, to a lesser extent, desktop personal computers with built-in speakers. Many of these devices use what are commonly referred to as “micro speakers.” Micro speakers are a miniaturized version of a loudspeaker, which use a moving coil motor to drive sound output. The moving coil motor may include a diaphragm (or sound radiating surface), voice coil and magnet assembly positioned within a frame. The input of an electrical audio signal to the moving coil motor causes the diaphragm to vibrate and output sound. The sound may be output from the sound output surface of the diaphragm to a sound output port through a front volume chamber that acoustically couples to the sound output face to the output port. A back volume chamber may be formed around the opposite face of the diaphragm to enhance sound output quality. Micro speaker performance is dependent on volume efficiency. Due to increasing demands for relatively low profile devices, particularly in the z-height dimension, however, it is becoming increasingly difficult to maximize an acoustic volume of the front and back volume chambers.